Hydro-formed t-fitting

ABSTRACT

A punch for forming opposite ends of a copper tube into a T includes a tapered or shovel-nose such that the spacing between the ends of the opposed punches is reduced, thereby reducing the excess copper remaining in the T once formed. A method of forming the fitting employs the shovel-nose punches in a hydro-forming process to accommodate such results.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.12/883,658, entitled T-FITTING MANUFACTURING METHOD AND TOOL, filed Sep.16, 2010, which claims priority under 35 U.S.C. §119(e) of U.S.Provisional Application No. 61/243,563 entitled T-FITTING MANUFACTURINGMETHOD AND TOOL, filed on Sep. 28, 2009, by John W. Schiabach, theentire disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to the manufacturing of copper T-fittings.

FIG. 1 shows a diagram of prior art T-fittings manufactured by ahydro-forming process utilizing generally cylindrical end punches, asseen in the prior art manufacturing equipment of FIG. 12. The punchesmove toward one another and engage a copper tube to compress the coppertube to form the orthogonal T-extension. The process includes thesubsequent steps of cutting the end of the extending orthogonal sectionand sizing all three openings of the T for final dimensioning. Withprior art processes and tooling, however, a relatively large amount ofcopper remains in the T at a position opposite the opening of theorthogonal T, as shown by arrow C in FIG. 1. In view of the increasingcost of copper, this material, which does not provide a useful functionto the T itself, is an unnecessary cost to the final product.

There exists a need, therefore, for a T-fitting design and manufacturingprocess in which the unnecessary material is eliminated while stillemploying the hydro-forming process.

SUMMARY OF THE INVENTION

The present invention reduces the amount of copper in a T-fitting byfrom 20% to 12% by providing a punch for forming opposite ends of acopper tube into a T, which includes a tapered or shovel-nose such thatthe spacing between the ends of the opposed punches is reduced, therebyreducing the excess copper remaining in the T once formed. The inventioninvolves both a method of forming the fitting employing the shovel-nosepunches in a hydro-forming process, the shape of the punch nose toaccommodate such results, and the resultant fitting.

These and other features, objects and advantages of the presentinvention will become apparent upon reading the following descriptionthereof together with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a conventional T-fittingmanufactured according to the prior art;

FIG. 2 is an improved T-fitting manufactured according to the presentinvention utilizing the tooling of the present invention;

FIG. 3 is a left end view of the fitting shown in FIG. 2;

FIG. 4 is a perspective view of one of the punch noses employed forcompressing opposite ends of a copper pipe to form the T-fitting shownin FIGS. 2 and 3;

FIG. 5 is a cross-sectional view of the punch nose;

FIG. 6 is a bottom view of the punch nose;

FIG. 7 is a front elevational view of the punch nose;

FIG. 8 is a top view of the punch nose;

FIG. 9 is a side elevational view, partly in phantom, of the punch nose;

FIG. 10 is an exploded fragmentary view taken in the circled area X inFIG. 9;

FIG. 11 is a right end elevational view of the punch nose; and

FIG. 12 is a schematic view of the prior art hydro-forming press.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring initially to FIG. 1, there is shown a conventional T-fitting10 in which a copper tube is formed by compressing under water at highpressure (about 10,000 psi) utilizing cylindrical punch nosescompressing a straight section of cylindrical copper pipe in oppositedirections indicated by arrows A and B in FIGS. 1 and 2. The result is adomed cylindrical orthogonal T-extension 14 (FIG. 12) to the otherwisecylindrical pipe 12. The enclosed end of domed extension 14 is cut in asecond step, after which each of the three open ends is sized in asizing guide to form the finished product. The cylindrical punches areinserted in the pipe in opposite directions as indicated by arrows A andB, however, resulting in a buildup of copper in the area indicated byarrow C in FIG. 1. This extends substantially the width of the of thediameter of the T-section 14. This buildup of copper material providesno additional strength or functional value to the T-fitting 10 andrepresents a waste of material.

In order to reduce the excess material in area C (FIG. 1), a new fitting20 has been devised utilizing improved punch noses shown in FIGS. 4-11.In fitting 20, a straight cylindrical section of copper tube 22 is againformed into a T by utilizing the shovel-nose punches 50 of theconfiguration shown in FIGS. 4-11 in the hydro-forming equipment of FIG.12 instead of the standard cylindrical prior art punch noses. Theprocess takes place in a hydro-forming machine at a high pressure ofabout 10,000 psi. The utilization of the shovel or tapered punchesresults in a much smaller buildup of copper in the area shown by arrow Din FIG. 2, which results in a 10% to 12% copper savings for theT-fitting 20 as compared to the T-fitting 10 for a given diameterfitting.

The method of manufacturing “T” 20 involves three steps, the first stepbeing placing a copper tube of a diameter ⅛″ to about 4″ and having alength slightly longer than the desired final length of the T in a pairof dies in a hydro-forming machine. The lower die is semi-cylindricaland an upper die has the same shape but has a cylindrical opening toallow the projection 24 of fitting 20 to extend through the top die.Punches 50 are pushed in opposite ends to force the ductile copper(which is from 95% to 99% pure) through the opening in the upper dieforming an extension 14 which, after the first step, is capped with acopper dome. The partially formed T is then removed from thehydro-forming press, which can be a press that is commercially availablefrom Schuler, such as shown in FIG. 12, and placed in a second die,which provides an alignment slot and chisel-like knife for slicing thedomed end of projection 24 off, forming the open end 25 of the T, whichalso includes open ends 21 and 23, as seen in FIGS. 2 and 3. Finally, afinishing step is provided by placing the T-fitting 20 in a final diewith three punches entering each of the openings 21, 23, and 25 toprovide the final sizing and dimensions for receiving correspondingpipes in a plumbing system.

As can be seen by comparing FIGS. 1 and 2, a significant percentage ofcopper is saved by reducing the amount of copper shown by arrow C inFIG. 1 to a significantly smaller amount, as shown by arrow D in FIG. 2.The reduction in the amount of copper in that particular area can be asmuch as 300% or more and represents an overall copper savings for theT-fitting of from 10% to 12%. The ability to manufacture fitting 20 asshown in FIGS. 2 and 3 is achieved by the shape of the shovel-nose punch50 shown in FIGS. 4-11. One such punch is used at each of the open ends21 and 23 (FIG. 2) by the hydro-forming machine 30 (FIG. 12).

Punch 50 includes a first end 52 which is coupled to a source ofpressurized fluid, such as water, at a pressure of 10,000 pounds or thelike and has a generally cylindrical body 54 terminating in ashovel-nosed end 56. A cylindrical longitudinally extending passageway55 allows water to pressurize the internal volume of the copper pipeplaced in the hydro-forming press. The end 56 includes a lower taperedlip 58 (tapered at about 45°) extending forwardly and concavely curvedthrough an arc of approximately 120°. Lip 58 is tapered upwardly to theopening 55 by a tapered conical transition zone 57 and lead-in zone 59.Zone 57 circumscribes an arc of about 82° (FIG. 5). The top 51 of theshovel-nose punch is also tapered at 61 at about 45° to form asemi-conical surface.

The hydro-forming machine uses two identical punches 50 with one on eachend and the shovel-nosed ends 58 align with the lower section 27 (FIG.2) of the fitting 20 during the forming process, such that the edges 58of the punch form the edges 26 and 28 of the copper shown by arrow D inFIG. 2. By providing an outwardly projecting nose 56 and the angled enddefined by side walls 63 and 65 terminating in the upper annular end 51(FIGS. 4, 7, and 8) allows the shovel-nose design of punch 50 when usedin a hydro-forming process to form the fitting shown in FIGS. 2 and 3with a reduced amount of excess copper, thereby greatly reducing thecost of the fitting itself and yet providing the same high qualityT-fitting available with the prior art processes. The dimensions of thepunch 50 are proportionally varied depending on the size of T-fitting 20being manufactured, although the shovel-nose shape remains substantiallyas shown.

It will become apparent to those skilled in the art that the exact shapeof the punch nose may be varied, as will the dimensions for differentsize T-fittings, without departing from the spirit or scope of theinvention as defined by the appended claims.

The invention claimed is:
 1. A copper T-fitting comprising: a first legand a second leg extending orthogonally from said first leg and whereinsaid fitting is made using hydro-forming with a shovel-nose punch shapedto reduce the amount of copper in the area of said first leg facing saidsecond leg.
 2. A T-fitting made by the process comprising the steps of:inserting a copper tube in a hydro-forming die; and applying ashove-nose tapered punch to opposite ends of said tube to form aT-fitting having a first leg and a second leg orthogonal to said firstleg wherein said first leg has a reduced amount of copper in the areaforming said second leg.
 3. A ductile metal T-fitting comprising: afirst cylindrical leg extending in a generally horizontal direction andhaving an interior wall with an inner diameter; and a second cylindricalleg extending orthogonally from and communicating with said first leg,wherein the interior wall of said first leg in the area aligned with theaxis of said second leg has an increased thickness that encompasses anarea less than the diameter of said second leg.
 4. The T-fitting asdefined in claim 3 wherein the area of increased thickness is one-thirdthe inner diameter of said first cylindrical leg.
 5. The T-fitting asdefined in claim 4 wherein said fitting is made of copper.
 6. A copperT-fitting comprising: a first cylindrical leg and a second cylindricalleg extending orthogonally from said first leg, wherein the interiorwall of said first leg in the area aligned with the longitudinal axis ofsaid second leg has a size less than the diameter of said second leg toreduce the amount of copper in the area of said first leg facing saidsecond leg.
 7. The T-fitting as defined in claim 6 wherein the area ofincreased thickness is one-third the inner diameter of said firstcylindrical leg.
 8. The T-fitting as defined in claim 7 wherein saidfitting is made by the process of inserting a copper tube in ahydro-forming die, and applying a shove-nose tapered punch to oppositeends of said tube to form a T-fitting having a first leg and a secondleg orthogonal to said first leg wherein said first leg has a reducedamount of copper in the area forming said second leg.